351 research outputs found
Final Report: Research Study on Development of Environmental Friendly Spray-on Foam Insulation (SOFI) for the External Tank (ET)
The selection and quantification of four foams using a more environmentally friendly HCFC-141b blowing agent replacing foams that used the CFC-11 blowing agent for the external tank (ET) LWT has been addressed along with problems and solutions that were encountered during verification. The effort on two lower density spray foams for the ET SLWT are presented, but predicted weight savings were not encouraging. Suggestions for possible problem solving are included along with a new approach for selecting foams for qualification as back-up foams for the foams used on the ET LWT. We investigated three resins for use as thermally sprayed coatings for corrosion prevention on metal. The best coating was obtained with a thermoplastic polyimide resin. This coating has a good chance of meeting ET requirements. Possible third generation blowing agents have been shown usable in polyurethane spray and pour foams, and solubility in isocyannate foam components are acceptable. We considered aerogels as insulation materials on space vehicles, and suggested a liner for a liquid oxygen (LOX) composite tank
Development of a run by run control benchmarking and simulation system
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1998.Includes bibliographical references (p. 68-69).As the semiconductor industry begins to move toward the introduction of fault detection and classification as well as run by run (RbR) process control methodologies, the identification of application scenarios and the means to compare and benchmark available solutions is an essential step. That step has been taken for FDC, and its importance for RbR has been recognized. The work presented here examines the feasibility of such an activity for run by run control including the determination of appropriate scenarios for run by run control, and determining how meaningful comparisons or benchmarking between controllers can be accomplished. There have been a number of benefits as a result of this project. First, we have shown that the benchmarking of run by run controllers is indeed feasible, and through the development of a run by run control simulation and benchmarking framework, and the determination of a set of process scenarios, SEMATECH is well-prepared for future efforts that might undertake benchmarking and/or demonstration of available commercial and experimental run by run controllers in specific realistic scenarios. Second, we now have a better understanding of the demands on and capabilities of run by run control, as well as a better understanding of the requirements of a successful benchmarking system. This information has been obtained through a literature survey and a questionnaire distributed to SEMATECH member companies to solicit feedback on the requirements and opportunities for run by run control and run by run control benchmarking. Third, we have defined and implemented several control scenarios that can serve as benchmarking cases in a future benchmarking effort. And finally, experience has been gained in using messaging protocols to connect RbR controllers to process simulators (or actual process tools) that can be beneficial in defining a standard set of communications for RbR controllers and other process peripherals.by Eric J. Stuckey.S.M
Two substrate-targeting sites in the Yersinia protein tyrosine phosphatase co-operate to promote bacterial virulence
YopH is a protein tyrosine phosphatase and an essential virulence determinant of the pathogenic bacterium Yersinia. Yersinia delivers YopH into infected host cells using a type III secretion mechanism. YopH dephosphorylates several focal adhesion proteins including p130Cas in human epithelial cells, resulting in disruption of focal adhesions and cell detachment from the extracellular matrix. How the C-terminal protein tyrosine phosphatase domain of YopH targets specific substrates such as p130Cas in the complex milieu of the host cell has not been fully elucidated. An N-terminal non-catalytic domain of YopH binds p130Cas in a phosphotyrosine-dependent manner and functions as a novel substrate-targeting site. The structure of the YopH protein tyrosine phosphatase domain bound to a model phosphopeptide substrate was solved and the resulting structure revealed a second substrate-targeting site (‘site 2’) within the catalytic domain. Site 2 binds to p130Cas in a phosphotyrosine-dependent manner, and co-operates with the N-terminal domain (‘site 1’) to promote efficient recognition of p130Cas by YopH in epithelial cells. The identification of two substrate-targeting sites in YopH that co-operate to promote epithelial cell detachment and bacterial virulence reinforces the importance of protein–protein interactions for determining protein tyrosine phosphatase specificity in vivo , and highlights the sophisticated nature of microbial pathogenicity factors.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73103/1/j.1365-2958.2005.04477.x.pd
Proceedings of the 11th Annual Meeting, Southern Soybean Disease Workers (March 27-29, 1984, Ft. Walton Beach, Florida): Economics of Soybean Disease
Contents
1984 Southern Soybean Disease Workers Officers
1984 Southern Soybean Disease Workers Program Committee
1984 Southern Soybean Disease Workers Committee Chairmen
Workshop
Diagnosing early season soybean disorders. D Stuckey and A Wrather
General session
Presidential address. HJ Walters
Southern United States Soybean Disease Loss Estimate for 1983. Southern Soybean Disease Workers, Soybean Disease Loss Estimate Committee. RP Mulrooney
Soybean nematodes. R Dunn presiding
A New Publication on the Soybean Cyst Nematode. WF Moore
Soybean Cultivars and Development of Populations of Meloidogyne incognita in Soil: A Concept of Tolerance. R RodrÃguez-Kábana and DB Weaver
A Comparison of Soybean Cultivars for Their Resistance to Meloidogyne incognita and M. arenaria. RA Kinloch
Ethylene Dibromide and Alternative Nematicides for Soybeans. RA Dunn
Involvement of Fungi in Phytonematode Pathology. G Morgan-Jones and R RodrÃguez-Kábana
Graduate student presentations. EC McGawley presiding
Interaction Between Heterodera glycines and Glomus macrocarpus on Soybeans as Affected by Aldicarb. DP McCormack, DP Schmitt, and KR Barker
Phomopsis sp. and Soybean Seedling Emergence: Influence of Soil Water Potential. M Gleason and RS Ferriss
Soybean seed, seedling and soil-borne diseases. WS Gazaway presiding
Report of Southern Soybean Disease Workers Seed Treatment Committee, 1983. MC McDaniel
Effects of Soil Source, Soil Moisture, Seed Quality and Seed Treatment on Soybean Emergence. RE Stuckey, RS Ferriss, and MR Siegel
Epidemiological and Mycofloral Relationships in Soybean Seedling Disease. JF Killebrew and KW Roy
Seed Treatments for Control of Seedling Diseases and Rhizoctonia Root Rot in No-Till Soybeans. AY Chambers
Soybean foliar, pod and stem diseases. JW Shriver presiding
Southern Soybean Disease Workers Standardized Foliar Fungicide Test, 1983. AY Chambers and MA Newman
Stem Canker in the Southeastern United States. WS Gazaway
Timings of Foliar Fungicide Applications on Soybeans in Louisiana. JS Gershey, GT Berggren, and ME Pace
Levels of Chlorine in Leaves and Seed Causing Leaf Scorch of Soybeans. MB Parker, TP Gaines, and GJ Gascho
Incidence and Yield Loss Estimates on Stem and Foliar Diseases as Affected by Row Spacing and Overhead Irrigation. MC Hirrell and MC McDaniel
Foliar Fungicides in Georgia: A Ten-Year Summary. DV Phillips
New developments. E Barrett presiding
The Use of Microcomputers in Soybean Disease Research. ME Pace, GT Berggren, Jr, and JS Gershey
Aerial Web Blight in Mississippi in 1983. JA Fox
SSDW Treasurer\u27s repor
MurTree: Optimal Classification Trees via Dynamic Programming and Search
Decision tree learning is a widely used approach in machine learning,
favoured in applications that require concise and interpretable models.
Heuristic methods are traditionally used to quickly produce models with
reasonably high accuracy. A commonly criticised point, however, is that the
resulting trees may not necessarily be the best representation of the data in
terms of accuracy and size. In recent years, this motivated the development of
optimal classification tree algorithms that globally optimise the decision tree
in contrast to heuristic methods that perform a sequence of locally optimal
decisions. We follow this line of work and provide a novel algorithm for
learning optimal classification trees based on dynamic programming and search.
Our algorithm supports constraints on the depth of the tree and number of
nodes. The success of our approach is attributed to a series of specialised
techniques that exploit properties unique to classification trees. Whereas
algorithms for optimal classification trees have traditionally been plagued by
high runtimes and limited scalability, we show in a detailed experimental study
that our approach uses only a fraction of the time required by the
state-of-the-art and can handle datasets with tens of thousands of instances,
providing several orders of magnitude improvements and notably contributing
towards the practical realisation of optimal decision trees
Ultraviolet refractive index values of organic aerosol extracted from deciduous forestry, urban and marine environments
The refractive index values of atmospheric aerosols are required to address the large uncertainties in the magnitude of atmospheric radiative forcing and measurements of the refractive index dispersion with wavelength of particulate matter sampled from the atmosphere are rare over ultraviolet wavelengths. An ultraviolet-optimized spectroscopic system illuminates optically-trapped single particles from a range of tropospheric environments to determine the particle's optical properties. Aerosol from remote marine, polluted urban, and forestry environments is collected on quartz filters, and the organic fraction isextracted and nebulized to form micron-sized spherical particles. The radius and the real component of refractive index dispersion with wavelength of the optically trapped particles are determined to a precision of 0.001 mm and 0.002 respectively over a near-ultraviolet-visible wavelength range of 0.320–0.480 mm. Remote marine aerosol is observed to have the lowest refractive index (n = 1.442 (l = 0.350 mm)), with above-canopy rural forestry aerosol (n = 1.462–1.481 (l = 0.350 mm)) and polluted urban aerosol (n = 1.444–1.485 (l = 0.350 mm)) showing similar refractive index dispersions with wavelength. In-canopy rural forestry aerosol is observed to have the highest refractive index value (n = 1.508 (l = 0.350 mm)). The study presents the first single particle measurements of the dispersion of refractive index with wavelength of atmospheric aerosol samples below wavelengths of 0.350 mm. The Cauchy dispersion equation, commonly used to describe the visible refractive index variation of aerosol particles, is demonstrated to extend to ultraviolet wavelengths below 0.350 mm for the urban, forestry, and atmospheric aerosol water-insoluble extracts from these environments. A 1D radiative-transfer calculation of the difference in top-of-the-atmosphere albedo between atmospheric core–shell mineral aerosol with and without films of this material demonstrates the importance of organic films forming on mineral aerosol
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